For implementing evidence-based interventions, having correct, relevant, and actionable data is extremely important. Our well-tailored Geographical Information System (GIS) helps us harness the power of geo-visualization for effective planning and monitoring of our projects. Realizing that existing slum data is disjointed with reality, we started co-creating data with the communities and the ULB which brings clarity, comfort and confidence to all stakeholders. This data is validated by the ULBs and democratized by making it available in the public domain. The insights provided by data help us measure what we truly value, whether we have brought the desired change to the lives of the urban poor.